Stabilizer tube structure and manufacturing method thereof

Abstract

The invention provides a voltage-regulator tube structure, which comprises a substrate, a shallow trench formed on the substrate, a trench inner wall isolation layer formed on the shallow trench, and a P-type shallow inversion region formed on the surface of the shallow trench, filling the residual shallow trench to form shallow trench isolation; the deep trap is formed by ion implantation, the doped trap is located on the deep trap, the doping type of the deep trap, the doped trap and the voltage-regulator tube ion implantation region is N type, and shallow trench isolation is arranged between the doped trap and the voltage-regulator tube ion implantation region; the N-type heavily doped region is positioned on the doped well; and the P-type heavily doped region is positioned above the ion implantation region of the voltage-regulator tube. The current path of the voltage-regulator tube is far away from the surface of the shallow trench isolation and flows from the N-type heavily doped region to the P-type heavily doped region, so that the influence of surface defects and interface states of the shallow trench isolation on the working current is reduced, and the performance and reliability of the voltage-regulator tube are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a voltage regulator tube structure and a manufacturing method thereof. Background Art

[0002] The cross-sectional structure of a conventional voltage regulator (ZENER) is as follows: Figure 1 As shown, ZNIMP is an N-type injection. When the device is working, the current flows from the N+ at the bottom of the STI to the P+ (as shown in Figure 2 As shown in the figure, because of the defects and interface states in STI (shallow trench isolation) etching and silicon interface, the performance and reliability of the Zener diode will be reduced when it works for a long time or at high temperature.

[0003] In order to solve the above problems, it is necessary to propose a new voltage regulator tube structure and a manufacturing method thereof. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a Zener diode structure and a manufacturing method thereof, so as to solve the problem that in the prior art Zener diode, there are defects and interface states in shallow trench isolation etching and silicon interface, which will cause the performance and reliability of the Zener diode to decrease when working for a long time or at high temperature.

[0005] In order to achieve the above-mentioned object and other related objects, the present invention provides a voltage regulator tube structure, comprising:

[0006] A substrate, a shallow trench is formed on the substrate, a trench inner wall isolation layer is formed on the shallow trench, and a P-type shallow inversion region is formed on the surface of the shallow trench;

[0007] Filling the remaining shallow trenches to form shallow trench isolation;

[0008] A deep well formed by ion implantation, a doped well located on the deep well, and a Zener tube ion implantation area, wherein the doping type of the deep well, the doped well, and the Zener tube ion implantation area is N-type, and there is shallow trench isolation between the doped well and the Zener tube ion implantation area; and an N-type heavily doped area located on the doped well and a P-type heavily doped area located above the Zener tube ion implantation area.

[0009] Preferably, the doping ions in the shallow inversion zone are boron ions.

[0010] Preferably, the shallow trench isolation is made of a material of spin-on-glass, a dense oxide formed by high-density plasma chemical vapor deposition, silicon dioxide, or double filling of silicon dioxide and silicon nitride.

[0011] Preferably, a buried layer is formed below the deep well.

[0012] Preferably, deep trench isolation is also formed on the substrate to isolate the voltage regulator tube and other devices.

[0013] The present invention also provides a method for manufacturing the above voltage regulator tube structure, comprising:

[0014] Step 1, providing a substrate, forming a shallow trench on the substrate, forming a trench inner wall isolation layer on the shallow trench, and forming a shallow inversion region on the surface of the shallow trench by P-type ion implantation;

[0015] Step 2, filling the remaining shallow trenches to form shallow trench isolation;

[0016] Step three, using ion implantation to form a deep well, a doped well located on the deep well, and a Zener diode ion implantation area, wherein the doping type of the deep well, the doped well, and the Zener diode ion implantation area is N-type, and there is shallow trench isolation between the doped well and the Zener diode ion implantation area; as well as an N-type heavily doped area located on the doped well and a P-type heavily doped area located above the Zener diode ion implantation area.

[0017] Preferably, the doping ions in the shallow inversion zone in step 1 are boron ions.

[0018] Preferably, the shallow trench isolation material in step 2 is spin-on-glass, dense oxide formed by high-density plasma chemical vapor deposition, silicon dioxide, or double filling of silicon dioxide and silicon nitride.

[0019] Preferably, a buried layer is formed below the deep well.

[0020] Preferably, deep trench isolation is also formed on the substrate to isolate the voltage regulator tube and other devices.

[0021] As described above, the voltage regulator tube structure and the manufacturing method thereof of the present invention have the following beneficial effects:

[0022] The current path of the voltage regulator tube of the present invention flows from the N-type heavily doped area to the P-type heavily doped area away from the shallow trench isolation surface, reducing the influence of shallow trench isolation surface defects and interface states on the working current and improving the performance and reliability of the voltage regulator tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Shown is a schematic diagram of the structure of a voltage regulator tube in the prior art;

[0024] Figure 2 Shown is a schematic diagram of the current path of a voltage regulator tube in the prior art;

[0025] Figure 3 Shown is a schematic diagram of the voltage regulator tube structure of the present invention;

[0026] Figure 4 It is a schematic diagram of the current path of the voltage regulator tube of the present invention. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] See also Figure 3 The present invention provides a voltage regulator tube structure, comprising:

[0029] A substrate 101, a shallow trench is formed on the substrate 101, a trench inner wall isolation layer 103 is formed on the shallow trench, a P-type shallow inversion region 104 is formed on the surface of the shallow trench, and the P-type shallow inversion region 104 can reduce the surface electric field of the shallow trench isolation 105;

[0030] In some embodiments, the doping ions of the shallow inversion zone 104 are boron ions, and the shallow inversion zone 104 needs to be adjusted with appropriate energy and dosage. In other embodiments, the doping ions of the shallow inversion zone 104 may also be other P-type ions.

[0031] Filling the remaining shallow trenches to form shallow trench isolation 105;

[0032] In some embodiments, the material of the shallow trench isolation 105 is spin-on-glass, dense oxide formed by high-density plasma chemical vapor deposition, silicon dioxide, or double filling of silicon dioxide and silicon nitride.

[0033] A deep well 111, a doped well 106 on the deep well 111, and a Zener diode ion implantation region 108 are formed by ion implantation. The doping type of the deep well 111, the doped well 106, and the Zener diode ion implantation region 108 is N-type, and there is a shallow trench isolation 105 between the doped well 106 and the Zener diode ion implantation region 108; and an N-type heavily doped region 107 on the doped well 106 and a P-type heavily doped region 109 above the Zener diode ion implantation region 108.

[0034] In some embodiments, a buried layer 110 is further formed below the deep well 111 .

[0035] In some embodiments, a deep trench isolation 102 is formed on the substrate 101 to isolate the Zener diode and other devices.

[0036] See also Figure 4According to the simulation results, the appropriate P-type ion implantation has no effect on the breakdown voltage of the Zener diode. The current path of the Zener diode is far away from the surface of the shallow trench isolation 105 and flows from the N-type heavily doped area 107 to the P-type heavily doped area 109, which reduces the influence of the surface defects and interface states of the shallow trench isolation 105 on the working current and improves the performance and reliability of the Zener diode.

[0037] The present invention also provides a method for manufacturing the above voltage regulator tube structure, comprising:

[0038] Step 1, providing a substrate 101, forming a shallow trench on the substrate 101, forming a trench inner wall isolation layer 103 on the shallow trench, and forming a shallow inversion region 104 on the surface of the shallow trench by P-type ion implantation, wherein the P-type shallow inversion region 104 can reduce the surface electric field of the shallow trench isolation 105;

[0039] In some embodiments, the doping ions of the shallow inversion zone 104 in step 1 are boron ions, and the shallow inversion zone 104 needs to be adjusted with appropriate energy and dosage. In other embodiments, the doping ions of the shallow inversion zone 104 can also be other P-type ions.

[0040] Step 2: Fill the remaining shallow trenches to form shallow trench isolation 105; the shallow trench isolation 105 can be formed by a deposition and polishing method, and the deposition method can be chemical vapor deposition, atomic layer deposition, etc.; the polishing method is chemical mechanical planarization polishing.

[0041] In some embodiments, the material of the shallow trench isolation 105 in step 2 is spin-on-glass, dense oxide formed by high-density plasma chemical vapor deposition, silicon dioxide, or double filling of silicon dioxide and silicon nitride.

[0042] Step 3: Use ion implantation to form a deep well 111, a doped well 106 located on the deep well 111, and a voltage regulator ion implantation region 108. The doping type of the deep well 111, the doped well 106, and the voltage regulator ion implantation region 108 is N-type, and there is a shallow trench isolation 105 between the doped well 106 and the voltage regulator ion implantation region 108; and an N-type heavily doped region 107 located on the doped well 106, and a P-type heavily doped region 109 located above the voltage regulator ion implantation region 108, forming a Figure 3 The structure shown.

[0043] In some embodiments, a buried layer 110 is further formed below the deep well 111 .

[0044] In some embodiments, a deep trench isolation 102 is formed on the substrate 101 to isolate the Zener diode and other devices.

[0045] See also Figure 4According to the simulation results, the appropriate P-type ion implantation has no effect on the breakdown voltage of the Zener diode. The current path of the Zener diode is far away from the surface of the shallow trench isolation 105 and flows from the N-type heavily doped area 107 to the P-type heavily doped area 109, which reduces the influence of the surface defects and interface states of the shallow trench isolation 105 on the working current and improves the performance and reliability of the Zener diode.

[0046] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0047] In summary, the current path of the voltage regulator tube of the present invention is far away from the shallow trench isolation surface and flows from the N-type heavily doped area to the P-type heavily doped area, reducing the influence of the shallow trench isolation surface defects and interface states on the working current, and improving the performance and reliability of the voltage regulator tube. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0048] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A voltage regulator tube structure, characterized in that: include: A substrate, a shallow trench is formed on the substrate, a trench inner wall isolation layer is formed on the shallow trench, and a P-type shallow inversion region is formed on the surface of the shallow trench; Filling the remaining shallow trenches to form shallow trench isolation; A deep well formed by ion implantation, a doped well located on the deep well, and a Zener tube ion implantation area, wherein the doping type of the deep well, the doped well, and the Zener tube ion implantation area is N-type, and there is shallow trench isolation between the doped well and the Zener tube ion implantation area; and an N-type heavily doped area located on the doped well and a P-type heavily doped area located above the Zener tube ion implantation area.

2. The voltage regulator tube structure according to claim 1, characterized in that: The doping ions of the shallow inversion zone are boron ions.

3. The voltage regulator tube structure according to claim 1, characterized in that: The shallow trench isolation is made of spin-on-glass, dense oxide formed by high-density plasma chemical vapor deposition, silicon dioxide, or double filling of silicon dioxide and silicon nitride.

4. The voltage regulator tube structure according to claim 1, characterized in that: A buried layer is also formed below the deep well.

5. The voltage regulator tube structure according to claim 1, characterized in that: A deep trench isolation is also formed on the substrate to isolate the voltage regulator tube and other devices.

6. The method for manufacturing a voltage regulator tube structure according to any one of claims 1 to 5, characterized in that: At least: Step 1, providing a substrate, forming a shallow trench on the substrate, forming a trench inner wall isolation layer on the shallow trench, and forming a shallow inversion region on the surface of the shallow trench by P-type ion implantation; Step 2, filling the remaining shallow trenches to form shallow trench isolation; Step three, using ion implantation to form a deep well, a doped well located on the deep well, and a Zener diode ion implantation area, wherein the doping type of the deep well, the doped well, and the Zener diode ion implantation area is N-type, and there is shallow trench isolation between the doped well and the Zener diode ion implantation area; as well as an N-type heavily doped area located on the doped well and a P-type heavily doped area located above the Zener diode ion implantation area.

7. The method for manufacturing a voltage regulator tube structure according to claim 6, characterized in that: The doping ions in the shallow inversion zone in step 1 are boron ions.

8. The method for manufacturing a voltage regulator tube structure according to claim 6, characterized in that: The material of the shallow trench isolation in step 2 is spin-on glass, dense oxide formed by high-density plasma chemical vapor deposition, silicon dioxide, or double filling of silicon dioxide and silicon nitride.

9. The method for manufacturing a voltage regulator tube structure according to claim 6, characterized in that: A buried layer is also formed below the deep well.

10. The method for manufacturing a voltage regulator tube structure according to claim 6, characterized in that: A deep trench isolation is also formed on the substrate to isolate the voltage regulator tube and other devices.

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